US7500366B2 - Refrigerator with magnetic shield - Google Patents

Refrigerator with magnetic shield Download PDF

Info

Publication number
US7500366B2
US7500366B2 US11/297,125 US29712505A US7500366B2 US 7500366 B2 US7500366 B2 US 7500366B2 US 29712505 A US29712505 A US 29712505A US 7500366 B2 US7500366 B2 US 7500366B2
Authority
US
United States
Prior art keywords
expander
magnetic shield
regenerative
regenerative type
type expander
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US11/297,125
Other languages
English (en)
Other versions
US20070130961A1 (en
Inventor
Mingyao Xu
Jin Lin Gao
Ralph C. Longsworth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Heavy Industries Ltd
Sumitomo SHI Cryogenics of America Inc
Original Assignee
Sumitomo Heavy Industries Ltd
Sumitomo SHI Cryogenics of America Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Heavy Industries Ltd, Sumitomo SHI Cryogenics of America Inc filed Critical Sumitomo Heavy Industries Ltd
Priority to US11/297,125 priority Critical patent/US7500366B2/en
Assigned to SHI-APD CRYOGENICS, INC. reassignment SHI-APD CRYOGENICS, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: GAO, JIN LIN, LONGSWORTH, RALPH C., XU, MINGYAO
Assigned to SUMITOMO HEAVY INDUSTRIES, LTD. reassignment SUMITOMO HEAVY INDUSTRIES, LTD. ASSIGNOR ASSIGNS 50% OF RIGHT, TITLE AND INTEREST TO ASSIGNEE Assignors: SHI-APD CRYOGENICS, INC.
Priority to JP2006324295A priority patent/JP4892328B2/ja
Priority to CN2006101659098A priority patent/CN101012982B/zh
Publication of US20070130961A1 publication Critical patent/US20070130961A1/en
Application granted granted Critical
Publication of US7500366B2 publication Critical patent/US7500366B2/en
Expired - Fee Related legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle
    • F25B9/145—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle pulse-tube cycle
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/3804—Additional hardware for cooling or heating of the magnet assembly, for housing a cooled or heated part of the magnet assembly or for temperature control of the magnet assembly
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/381—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets
    • G01R33/3815—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets with superconducting coils, e.g. power supply therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/003—Gas cycle refrigeration machines characterised by construction or composition of the regenerator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1408—Pulse-tube cycles with pulse tube having U-turn or L-turn type geometrical arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1415—Pulse-tube cycles characterised by regenerator details
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/10—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point with several cooling stages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D19/00—Arrangement or mounting of refrigeration units with respect to devices or objects to be refrigerated, e.g. infrared detectors
    • F25D19/006—Thermal coupling structure or interface

Definitions

  • Gifford McMahon (GM), GM type pulse tube, Stirling and Stirling type pulse tube refrigerators operating in a MRI cryostat are used to cool a superconducting magnet either by conduction through a direct connection between the cold end of the expander and the magnet, or by operating in a helium filled neck tube of the MRI cryostat where the refrigerator recondenses helium that is cooling the MRI magnet.
  • GM Gifford McMahon
  • GM type pulse tube, Stirling and Stirling type pulse tube refrigerators operating in a MRI cryostat are used to cool a superconducting magnet either by conduction through a direct connection between the cold end of the expander and the magnet, or by operating in a helium filled neck tube of the MRI cryostat where the refrigerator recondenses helium that is cooling the MRI magnet.
  • the rare earth materials have magnetic properties that cause them to interact with the magnetic field in the bore of the MRI magnet and result in noise being superimposed on the imaging signal.
  • This problem is described in JP 2600869 by Nagao, filed on 13 Dec. 1988, for a conventional GM refrigerator in which the rare earth material is contained in the reciprocating second stage displacer.
  • This patent describes several different designs of magnetic shields that prevent the rare earth material from introducing noise into the MRI signal.
  • the expanders are described as operating in the vacuum in the MRI cryostat; thus the magnetic shield can be attached to an expander heat station and cooled to a uniform temperature without heat transfer between the shield and the expander cylinder.
  • the expander plugs into the neck tube and can easily be removed to be serviced without warming the magnet. It comes into thermal contact with a first stage heat station in the neck tube that is connected to a thermal shield at about 40 K, and into thermal contact at the second stage 4 K heat station which is connected to a helium recondenser and a magnetic shield.
  • the magnetic shield is located on the vacuum side of the neck tube so that it is thermally isolated from the neck tube and the expander cylinder. Thermal conducting strips are layered with the superconducting shield material to keep the assembly near 4 K.
  • Two-stage GM type pulse tubes operating at 4 K introduce much less noise to a MRI signal than conventional two-stage GM expanders because the cold regenerator containing rare earth materials is stationary. However noise continues to be introduced either due to small motion from pressure cycling the pulse tube, or due to thermal cycling of the regenerator material.
  • GM expanders have the regenerators packed inside the displacer bodies, thus they reciprocate with the displacer.
  • This arrangement provides a compact design with a single stepped cylinder.
  • the helium gas in the neck tube transfers heat by convection between the neck tube and the expander cylinder. Thermal losses are minimized by mounting the neck tube in a near vertical orientation.
  • the expander cylinder and the neck tube have almost the same temperature gradients.
  • Pulse tube expanders typically have the regenerators in tubes that are spaced closely apart from the pulse tubes and parallel to them. When mounted in a MRI neck tube surrounded by helium gas the temperature differences between the regenerators and pulse tubes result in convective thermal losses between them, in addition to thermal losses due to heat exchange with the neck tube.
  • the magnet shield is attached at the outside of the cylinder, which requires a large size shield.
  • the shield is made of superconducting materials, which are expensive especially in a pulse tube refrigerator, where the 2nd stage heat station is much larger than that of a GM refrigerator.
  • the essential feature of this invention is a magnetic shield mounted in its own vacuum enclosure. When so mounted, it may surround cold magnetic regenerator material in a pulse tube, GM, or other regenerative type expander, and the enclosure can be in contact with helium gas that is in the expander or in the space around the expander.
  • the pulse tube or GM expander with a magnetic shield may be used to cool a superconducting MRI magnet to about 4 K in any of various applications.
  • the principal application of a pulse tube or GM expander with a magnetic shield is to cool a superconducting MRI magnet to about 4 K.
  • An expander with this invention can be mounted either in the MRI cryostat vacuum space or in a helium filled neck tube in the cryostat.
  • Convective thermal losses of a multi-stage 4 K pulse tube expander in a helium filled neck tube of a MRI cryostat are minimized by the vacuum enclosure that contains the magnetic shield.
  • the vacuum enclosure with the shield is part of the expander assembly and is removed with the expander when it is serviced. Depending on the type of superconducting material used in the shield, it can be cooled either by the first or second stage of the expander.
  • the shield is annular in shape and surrounds the magnetic regenerator material in a regenerative type expander.
  • An expander with this invention can be mounted either in the neck tube of a MRI cryostat or in the cryostat vacuum space. When mounted in the neck tube it may be surrounded by a gas such as helium. In the case of a pulse tube expander thermal losses between the regenerator, magnetic shield, pulse tube, and neck tube are minimized by the vacuum enclosure that contains the shield.
  • FIG. 1 is a cross section of an annular magnetic shield in an annular vacuum enclosure.
  • FIG. 2 is a schematic of a two-stage pulse tube expander with the magnetic shield of FIG. 1 . shown as an insert in the cold regenerator sleeve.
  • FIG. 3 is a schematic of a second embodiment of the present invention. It shows a two-stage pulse tube expander with the magnetic shield in an annular vacuum enclosure in which the cold regenerator sleeve is the outer wall of the vacuum enclosure.
  • FIG. 4 is a schematic of the present invention which shows the two-stage pulse tube of FIG. 2 mounted in the neck tube of a MRI cryostat where it is surrounded by helium gas.
  • FIG. 5 is a schematic of a third embodiment of the present invention showing a two-stage pulse tube with an annular magnetic shield that is contained in an annular vacuum enclosure that is external to the second stage regenerator sleeve.
  • FIG. 6 is a schematic of a fourth embodiment of the present invention which shows a two-stage pulse tube with an annular magnetic shield around the cold regenerator, both of which are contained in a vacuum enclosure that also contains the cold section of the second stage pulse tube.
  • FIG. 7 is a schematic of a fifth embodiment of the present invention. It shows a two-stage GM expander with the magnetic shield of FIG. 1 as an insert in the second stage cylinder.
  • This invention provides a means of placing a magnetic shield around the magnetic material in the cold end of a 4 K pulse tube or GM expander or other type expander.
  • the magnetic shield of this invention can be used with the expanders of Stirling refrigerators and Stirling type pulse tube refrigerators if there are advances in refrigerator technology. In general this invention can be used with any type of regenerative cooler.
  • the magnetic shield located within a vacuum enclosure that is part of the expander.
  • an annular vacuum enclosure is located inside the cold regenerator sleeve in the case of a pulse tube, or inside the cold cylinder in case of a GM expander.
  • the magnetic regenerator material is packed in the bore of the vacuum enclosure, while for a GM expander the cold displacer, which has magnetic regenerator material in it, reciprocates in the bore of the vacuum enclosure.
  • Pulse tube expanders are typically mounted in a near vertical orientation so the top of a pulse tube is synonymous with the warm end, and the bottom of the pulse tube is synonymous with the cold end.
  • Two-stage expanders are used to illustrate the principles of the invention but the invention also applies to any stage of an expander that contains magnetic materials. Such materials are typically only used in cold regenerators that are operating between 3 K and 40 K. The following examples all show the magnetic shield cooled by the second stage of the expander but if the magnetic shield is made of HTS material it may be cooled by the first stage of the expander.
  • FIG. 1 is a cross section of magnetic shield insert 70 which comprises annular magnetic shield 31 in annular vacuum enclosure 40 .
  • Magnetic shield 31 is thermally isolated from vacuum enclosure 40 except at one end where thermal base 32 conducts heat out the end of magnetic shield 31 .
  • Magnetic shield 31 is typically designed with enough thermally conductive material to keep it near the temperature of thermal base 32 , approximately 4 K, while vacuum enclosure 40 may have a temperature gradient and a temperature of about 40 K at the top end.
  • FIG. 2 is a schematic of two-stage pulse tube expander 71 with magnetic shield insert 70 inside cold regenerator sleeve 23 .
  • Second stage regenerator 24 comprises nonmagnetic material 26 at the warm end, type I magnetic material 27 in the middle, and type II magnetic material 28 at the cold end, all packed in the bore of magnetic shield insert 70 .
  • Two-stage pulse tube expander assembly 71 includes first stage pulse tube 10 , first stage regenerator 14 , second stage pulse tube 20 , (shown as having a warm end 20 a and a cold end 20 b ), second stage regenerator 24 warm flange 4 , warm flow smoothers 11 and 21 , cold flow smoothers 12 and 22 , first stage heat station 15 , second stage heat station 25 , and valve/orifice/buffer assembly 5 .
  • Tube 6 carries high pressure helium from the compressor (not shown) to the valve in 5
  • tube 7 returns helium at low pressure to the compressor.
  • First stage regenerator 14 is typically packed in a removable sleeve.
  • Heat station 15 has a removable flow distributor 16 that permits shield insert 70 with regenerator 24 in it to be installed from the warm end of the pulse tube. Gas is prevented from flowing between the outside of insert 70 and regenerator sleeve 23 by seal 29 .
  • the design is such that the cold end of insert 70 is brought into thermal contact with heat station 25 . It is typical to construct pulse tubes 10 and 20 , and the shells for regenerators 14 and 24 , from thin walled SS tubes to minimize axial conduction losses.
  • FIG. 3 shows two-stage pulse tube expander 72 with magnetic shield 31 in annular vacuum enclosure 41 in which cold regenerator sleeve 23 is the outer wall of the vacuum enclosure.
  • Magnetic shield 31 and vacuum enclosure 41 are thus an integral part of the pulse tube.
  • the inner bore of enclosure 41 contains regenerator 24 .
  • Magnetic shields are relatively expensive.
  • Expanders 71 and 72 both have small magnetic shields and are thus less expensive to manufacture relative to prior designs.
  • FIG. 4 is a schematic of the most common application of the present invention.
  • MRI cryostat with helium filled neck tube 60 is shown with two-stage pulse tube 71 inserted in it.
  • MRI cryostat assembly 60 consists of an outer housing 50 that is connected to inner vessel 55 by a neck tube, consisting of warm end neck tube 51 a , heat station 58 , and cold end neck tube 51 b .
  • Vessel 55 contains liquid helium 56 and superconducting MRI magnet 57 . It is surrounded by vacuum 53 .
  • a typical MRI cryostat has a radiation shield 54 that is cooled to about 40 K through 58 by first stage heat station 15 of pulse tube expander 71 .
  • Pulse tube 72 with an integral vacuum enclosure for the magnetic shield is functionally equivalent to expander 71 .
  • Heat station 15 is shown as being conically shaped to mate with neck tube heat station 58 .
  • Radial “O” ring 8 enables pulse tube 71 to be inserted into the neck tube until pulse tube heat station 15 is thermally engaged with neck tube heat station 58 .
  • This arrangement allows pulse tube expander 71 or 72 to be easily removed from MRI cryostat assembly 60 for service.
  • Helium gas 52 occupies the space between expander 71 and the neck tube in assembly 60 .
  • the pulse tube expander has first stage heat station 15 at about 40 K that is used to cool a shield in the magnet cryostat, and helium recondenser 25 at the second stage that keeps the superconducting MRI magnet near 4 K.
  • Vacuum enclosures 40 or 41 around magnetic shield 30 which have magnetic regenerator materials packed in the bore, provide thermal isolation between regenerator sleeve 23 , pulse tube 20 b , and neck tube sleeve 51 b , in the presence of helium 52 in the neck tube.
  • Second stage pulse tube 20 is shown as not being in physical contact with heat station 15 .
  • a two stage pulse operates in a vacuum there is an advantage in not having thermal contact.
  • helium surrounds the pulse tubes, it is less advantageous, but it is a choice of the designer.
  • FIG. 5 shows two-stage pulse tube assembly 73 which has annular vacuum enclosure 42 with vacuum space 43 surrounding magnetic shield 31 .
  • Second stage regenerator 24 with rare earth material is within the annular space of enclosure 42 .
  • Vacuum enclosure 42 and shield 31 are attached to second stage heat station 25 but do no not extend to first stage heat station 15 .
  • helium gas fills the annular space between regenerator sleeve 23 and vacuum enclosure 42 . This will tend to cause the temperature profiles in both to be similar. The thermal loss associated with this is small. Cost savings in manufacturing evacuated enclosure 42 with shield 31 as a subassembly may offset the small thermal loss.
  • FIG. 6 is a schematic of two-stage pulse tube 74 with an annular magnetic shield around the cold regenerator, both of which are in a vacuum enclosure that also contains the cold section of second stage pulse tube 20 b .
  • Magnetic shield 31 is physically and thermally attached to second stage heat station 25 .
  • Vacuum enclosure 44 extends from second stage heat station 25 to first stage heat station 15 .
  • Second stage pulse tube 20 is brazed to heat station 15 in order to maintain vacuum 43 within sleeve 44 .
  • conduction through the gas that fills the annular space between sleeve 44 and the neck tube in cryostat 60 will result in the temperature profiles in both tubes to be similar. Thermal losses due to convection will be small. Within enclosure 44 convection losses are eliminated.
  • FIG. 7 is a schematic of the lower section of two-stage GM expander 80 with the magnetic shield 70 of FIG. 1 as an insert in second stage cylinder 84 .
  • First stage displacer 81 is coupled to second stage displacer body 86 .
  • Displacer 81 reciprocates in cylinder 81 and produces refrigeration in the space at the cold end which receives heat from first stage heat station 83 .
  • Regenerator materials 26 , 27 , and 28 are packed in displacer body 86 which reciprocates in the bore of vacuum enclosure 70 .
  • Refrigeration is produced in the space at the cold end and heat is received from heat station 85 .
  • Static seal 29 prevents gas from by-passing between the outer wall of insert 70 and the inner wall of cylinder 84 .
  • Seal 87 on displacer body 86 prevents gas from by-passing the cold regenerator. It is noted that a grooved displacer body, as described in U.S. Pat. No. 5,481,879, incorporated herein by reference and made a part hereof, avoids the need for seal 87 .
  • FIG. 7 describes the use of removable insert 70
  • an integral vacuum enclosure with a magnetic shield similar to 41 as shown in FIG. 3 for pulse tube 72 , is a possible option.
  • the magnetic shield would be typical for the magnetic shield to be assembled into a sleeve that is then evacuated, but it is possible to leave residual gas, such as nitrogen, that is reduced to a very low pressure when the shield is cooled, either by virtue of the very low temperature or using an adsorbent such as charcoal.
  • Regenerative type expanders include GM, GM type pulse tubes, Stirling, and Stirling type pulse tubes. Depending on the material used in the magnetic shield, it can be cooled by either the first or second stage of the expander.
  • the superconductor shield is enclosed by a double-wall cartridge and the cartridge is inserted into the cylinder.
  • the cartridge can be tight fit into the cylinder or removable.
  • a double wall cartridge is used for the 2nd regenerator.
  • a double-wall displacer can be made as the 2nd displacer.
  • the double wall cartridge can be manually evacuated, and getter, such as charcoal, can be attached on the walls to keep the vacuum. Even though it is not evacuated, after cool down since the temperature is close to 4K at the cold end, most of the components in the air will have solidified, acting similarly to a heat switch.
  • a ⁇ 90 mm shield is needed if the shield is attached to the 2nd stage heat station. With the shield in accordance with this invention, only a ⁇ 35 mm shield is needed.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Containers, Films, And Cooling For Superconductive Devices (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
US11/297,125 2005-12-08 2005-12-08 Refrigerator with magnetic shield Expired - Fee Related US7500366B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US11/297,125 US7500366B2 (en) 2005-12-08 2005-12-08 Refrigerator with magnetic shield
JP2006324295A JP4892328B2 (ja) 2005-12-08 2006-11-30 磁気シールド付き冷凍機
CN2006101659098A CN101012982B (zh) 2005-12-08 2006-12-08 回热类型的膨胀机

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US11/297,125 US7500366B2 (en) 2005-12-08 2005-12-08 Refrigerator with magnetic shield

Publications (2)

Publication Number Publication Date
US20070130961A1 US20070130961A1 (en) 2007-06-14
US7500366B2 true US7500366B2 (en) 2009-03-10

Family

ID=38137920

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/297,125 Expired - Fee Related US7500366B2 (en) 2005-12-08 2005-12-08 Refrigerator with magnetic shield

Country Status (3)

Country Link
US (1) US7500366B2 (ja)
JP (1) JP4892328B2 (ja)
CN (1) CN101012982B (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120004109A1 (en) * 2010-06-30 2012-01-05 Anbo Wu Magnet assemblies and methods for temperature control of the magnet assemblies

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4404021B2 (ja) * 2005-06-30 2010-01-27 株式会社日立製作所 Ｍｒｉ用超電導磁石
JP2009293909A (ja) 2008-06-09 2009-12-17 Sumitomo Heavy Ind Ltd 蓄冷型膨張機、パルス管冷凍機、磁気共鳴イメージング装置、核磁気共鳴装置、超伝導量子干渉素子磁束計及び蓄冷型膨張機の磁気シールド方法
JP5212981B2 (ja) * 2008-08-21 2013-06-19 学校法人金沢工業大学 極低温冷却装置
JP5889743B2 (ja) 2012-07-20 2016-03-22 住友重機械工業株式会社 蓄冷式冷凍機
JP6305193B2 (ja) * 2013-09-17 2018-04-04 住友重機械工業株式会社 蓄冷式冷凍機、一段蓄冷器、及び二段蓄冷器
JP6109057B2 (ja) * 2013-12-16 2017-04-05 住友重機械工業株式会社 蓄冷器式冷凍機
GB201400201D0 (en) 2014-01-07 2014-02-26 Siemens Plc Exchange of a cold head in a superconducting magnet system
JP6214498B2 (ja) * 2014-09-02 2017-10-18 住友重機械工業株式会社 極低温冷凍機
JP6400262B1 (ja) * 2017-03-30 2018-10-03 住友重機械工業株式会社 極低温冷凍機および磁気シールド
JP6951889B2 (ja) * 2017-07-07 2021-10-20 住友重機械工業株式会社 極低温冷凍機、及び極低温冷凍機の磁気シールド構造

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3331041A (en) 1964-04-25 1967-07-11 Siemens Ag Superconductor device for shielding or collecting magnetic fields
US4803452A (en) 1985-02-08 1989-02-07 Yoshiro Saji Superconductor for magnetic field shielding
JPH02161260A (ja) 1988-12-13 1990-06-21 Mitsubishi Electric Corp 蓄冷式極低温冷凍機
US5447033A (en) * 1988-11-09 1995-09-05 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
US5481879A (en) 1994-05-31 1996-01-09 Sumitomo Heavy Industries, Ltd. Refrigerator having regenerator
US5638685A (en) * 1994-04-15 1997-06-17 Mitsubishi Denki Kabushiki Kaisha Superconducting magnet and regenerative refrigerator for the magnet
US5701744A (en) * 1996-10-31 1997-12-30 General Electric Company Magnetic resonance imager with helium recondensing
US6029458A (en) * 1998-05-07 2000-02-29 Eckels; Phillip William Helium recondensing magnetic resonance imager superconducting shield
US6256998B1 (en) 2000-04-24 2001-07-10 Igcapd Cryogenics, Inc. Hybrid-two-stage pulse tube refrigerator
US20040169515A1 (en) * 2003-02-28 2004-09-02 Yasunori Koga Superconductive magnet apparatus and magnetic resonance imaging apparatus
US20050253676A1 (en) * 2004-05-11 2005-11-17 Bruker Biospin Ag Magnet system with shielded regenerator material
US6990818B2 (en) * 2001-08-01 2006-01-31 Forschungszentrum Karlsruhe Gmbh Device for the recondensation, by means of a cryogenerator, of low-boiling gases evaporating from a liquid gas container
US7318318B2 (en) * 2004-03-13 2008-01-15 Bruker Biospin Gmbh Superconducting magnet system with refrigerator

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2726789B2 (ja) * 1992-11-20 1998-03-11 三菱電機株式会社 蓄冷型冷凍機
JPH10256614A (ja) * 1997-03-17 1998-09-25 Toshiba Corp 磁気シールド装置
JP2000266417A (ja) * 1999-03-15 2000-09-29 Sumitomo Heavy Ind Ltd 冷凍機用磁気シールド体
JP2001004237A (ja) * 1999-06-24 2001-01-12 Mitsubishi Electric Corp 極低温冷却装置および極低温冷却方法
JP4514346B2 (ja) * 2000-02-28 2010-07-28 大陽日酸株式会社 超電導部材冷却装置

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3331041A (en) 1964-04-25 1967-07-11 Siemens Ag Superconductor device for shielding or collecting magnetic fields
US4803452A (en) 1985-02-08 1989-02-07 Yoshiro Saji Superconductor for magnetic field shielding
US5447033A (en) * 1988-11-09 1995-09-05 Mitsubishi Denki Kabushiki Kaisha Multi-stage cold accumulation type refrigerator and cooling device including the same
JPH02161260A (ja) 1988-12-13 1990-06-21 Mitsubishi Electric Corp 蓄冷式極低温冷凍機
US5638685A (en) * 1994-04-15 1997-06-17 Mitsubishi Denki Kabushiki Kaisha Superconducting magnet and regenerative refrigerator for the magnet
US5481879A (en) 1994-05-31 1996-01-09 Sumitomo Heavy Industries, Ltd. Refrigerator having regenerator
US5701744A (en) * 1996-10-31 1997-12-30 General Electric Company Magnetic resonance imager with helium recondensing
US6029458A (en) * 1998-05-07 2000-02-29 Eckels; Phillip William Helium recondensing magnetic resonance imager superconducting shield
US6256998B1 (en) 2000-04-24 2001-07-10 Igcapd Cryogenics, Inc. Hybrid-two-stage pulse tube refrigerator
US6990818B2 (en) * 2001-08-01 2006-01-31 Forschungszentrum Karlsruhe Gmbh Device for the recondensation, by means of a cryogenerator, of low-boiling gases evaporating from a liquid gas container
US20040169515A1 (en) * 2003-02-28 2004-09-02 Yasunori Koga Superconductive magnet apparatus and magnetic resonance imaging apparatus
US7318318B2 (en) * 2004-03-13 2008-01-15 Bruker Biospin Gmbh Superconducting magnet system with refrigerator
US20050253676A1 (en) * 2004-05-11 2005-11-17 Bruker Biospin Ag Magnet system with shielded regenerator material

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120004109A1 (en) * 2010-06-30 2012-01-05 Anbo Wu Magnet assemblies and methods for temperature control of the magnet assemblies
US8581681B2 (en) * 2010-06-30 2013-11-12 General Electric Company Magnet assemblies and methods for temperature control of the magnet assemblies

Also Published As

Publication number Publication date
JP2007155319A (ja) 2007-06-21
JP4892328B2 (ja) 2012-03-07
CN101012982B (zh) 2011-10-26
US20070130961A1 (en) 2007-06-14
CN101012982A (zh) 2007-08-08

Similar Documents

Publication Publication Date Title
US7500366B2 (en) Refrigerator with magnetic shield
US7497084B2 (en) Co-axial multi-stage pulse tube for helium recondensation
US4510771A (en) Cryostat with refrigerating machine
US7568351B2 (en) Multi-stage pulse tube with matched temperature profiles
US5586437A (en) MRI cryostat cooled by open and closed cycle refrigeration systems
US20060021355A1 (en) Cryostat configuration
EP0392771B1 (en) Cryogenic precooler for superconductive magnet
US4827736A (en) Cryogenic refrigeration system for cooling a specimen
JPH11243007A (ja) 磁気共鳴イメージング用超電導磁石
JPH11159899A (ja) クライオスタット装置
JPH11151225A (ja) Ｍｒｉ（磁気共鳴映像）またはｎｍｒ（核磁気共鳴）システム
US7350363B2 (en) Pulse tube refrigerator sleeve
JPS6294769A (ja) 二段熱カツプリング
JPH0653035A (ja) 超電導マグネット
JP2008538856A (ja) クライオスタットアセンブリ
US11649989B2 (en) Heat station for cooling a circulating cryogen
JPH1026427A (ja) 冷却装置
WO2003036190A1 (en) A pulse tube refrigerator with an insulating sleeve
US11977139B2 (en) Accelerated cooldown of low-cryogen magnetic resonance imaging (MRI) magnets
JP2007078310A (ja) 極低温冷却装置
JP3843186B2 (ja) 極低温冷凍機のオーバーホール装置およびオーバーホ−ル方法
JPH0296304A (ja) 極低温容器
JP2893210B2 (ja) 高温超電導磁気シールド用クライオスタット
CN113724960A (zh) 用于低温系统的制冷机安装结构
JPH06283328A (ja) 極低温装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: SHI-APD CRYOGENICS, INC., PENNSYLVANIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:XU, MINGYAO;GAO, JIN LIN;LONGSWORTH, RALPH C.;REEL/FRAME:017235/0859;SIGNING DATES FROM 20060217 TO 20060221

AS Assignment

Owner name: SUMITOMO HEAVY INDUSTRIES, LTD., JAPAN

Free format text: ASSIGNOR ASSIGNS 50% OF RIGHT, TITLE AND INTEREST TO ASSIGNEE;ASSIGNOR:SHI-APD CRYOGENICS, INC.;REEL/FRAME:017526/0029

Effective date: 20060424

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20210310